The Philippine government is defending its efforts to deliver assistance to victims of Typhoon Haiyan, many of whom have received little or no assistance since the deadly storm struck a week ago.

Interior Secretary Mar Roxas said Friday that in a situation like this, nothing is fast enough. Speaking in the city of devasted city of Tacloban, he said that the need is massive, immediate and not everyone can be reached.

Disaster relief chief, Eduardo del Rosario, told reporters Friday that the official death toll from the storm has risen to 3,621.

Meanwhile, the U.S. Navy launched a huge relief operation Thursday.

The aircraft carrier USS George Washington and a contingent of seven supply ships began delivering water and emergency rations to Tacloban. The giant hospital ship USS Mercy also is making emergency preparations to depart the United States, and is expected to join the emergency flotilla within weeks, along with the British carrier HMS Illustrious.

As U.S. helicopters sped food and water to the city, reconnaissance aircraft began charting the worst-hit areas.

Deputy Chief of Mission for the U.S. Embassy in Manila Brian Goldbeck said he beleives the aid distrubution is going well so far.

"I think the key point here is that, a large volume of assistance was pushed through to Tacloban. Now what's happening, is that the MV-22s, the Ospreys, together with the helicopters from George Washington carrier strike group, together with the Philippines' own helicopters. All of those assets are now moving resources from Tacloban to multiple points , I think 16 or 18 different drop points, yesterday and today."

The flow of relief supplies has been hampered by wrecked roadways and the lack of gasoline in and near the city. Officials say the fuel shortages have been made worse by retail merchants afraid to sell their gasoline supplies for fear of rioting by an increasingly desperate population.

Also, Thursday, rescue personnel began the grim task of lowering unidentified bodies into a mass grave near Tacloban's city hall.

United Nations humanitarian chief Valerie Amos, who toured Tacloban Wednesday, called the situation "dismal," with tens of thousands of people living during monsoon season in the open and exposed to rain and wind.